Kōkakos are large New Zealand songbirds. Their diet consists mainly of fruit, leaves, and small invertebrates. Once plentiful in New Zealand’s lowland forests, predation from ship rats and invasive possums has made the Kōkako an endangered species. The remainder of their population, around 1,400 birds, is confined to the forests of the North Island of New Zealand. A South Island subspecies with orange wattles is likely extinct. Poor flyers, Kōkako use their long legs to ‘bound’ from tree to tree. They are known for their loud, complicated songs. Males and females may sing duets that last for up to half an hour.